At the end of a nuclear fuel cycle, spent nuclear fuel is typically stored on-site for future reprocessing or subsequent long-term storage. For transportation, spent nuclear fuel is often stored in a spent fuel storage cask. Typically, the casks are cylindrical in shape, made of steel and/or concrete, and oft times are transported and stored in a vertical orientation. A typical storage cask will be roughly 12 feet in diameter and weigh approximately 180 tons.
Various methods have been devised to lift and transport these casks, however most existing methods have drawbacks regarding maneuverability. These methods include using heavy-haul trailers or mobilized hydraulic gantry cranes attached to crawler type carriers. Another cask transporter, currently in use, consists of a hydraulic gantry mounted on a frame having eight on-center rigid suspension axle assemblies on which are mounted 16 large foam filled aircraft tires. Each of the current transporters and methods requires lifting the casks with some configuration of an overhead lifting beam or crane. As these transporters use an overhead lifting configuration, the transporters and methods must conform to strict Nuclear Regulatory Commission (NRC) safety standards. These standards include stringent single failure proof restrictions.
In addition, existing cask transporters typically rely on variations in tire pressure and tire compression to maintain lateral equalized loading on otherwise rigid axles. The reliance on tire pressure and/or compression alone is inadequate and may lead to severe overloading of the tires and/or bearings, and is the Achilles heel of most conventional heavy load transporters and trailers.
There exists a need for a highly maneuverable transporter capable of adjustable leveling to negotiate non-level surfaces and a wide variety of road surfaces. In addition, there exists a need for a lifting transporter to securely lift and transport spent nuclear fuel storage casks while conforming to the NRC safety standards.